Composite materials including thermoset resins and fibers have been employed in manufacturing of specialty articles. The processes using these materials are generally labor intensive and require long curing times. Although such processes may be suitable for various specialty applications, they are generally uneconomical compared with other processes, such as short cycle molding operations employed in thermoplastic molding processes. In thermoplastic molding processes, short cycle times can be achieved by injecting a molten thermoplastic into a relatively cold mold (i.e., below the melting temperature or softening temperature of the thermoplastic). and rapidly cooling the thermoplastic material in the mold so that the polymer stiffens sufficiently to be removed from the mold. However, in the case of thermoset materials, it is necessary to cure the thermoset resin which requires high cure temperatures and/or long cure times. Difficulties are also encountered when the thermoset resin is part of a composite material that includes fibers. For example WO 2010/046770 A1 describes making a polymer pre-impregnated reinforcement material using solid particles, but discourages the use of thermoset resins.
The use of dispersions of thermoplastic particles for making glass fibers thermoplastics is described in WO 02/46276 and WO 99/64216. However, the authors describe that such processes would not be useful with thermoset resins. As recognized by the prior art, the properties of thermoset materials, the difficulty of controlling their cure, presents difficulties in developing compositions with industrially applicable properties that can be economically processed, molded and produced into finished industrial parts, particularly when economics of mass production are required.
Although prepreg materials including a thermoset resin and a fiber are known in the art, these prepreg materials generally have some drawbacks. Some of these difficulties may be overcome by the use of high molecular weight thermoset resins, they may pose additional problems.
Therefore, there is a high desire in the pre-molding article and composite industry for an overall system of polymer matrix and fiber reinforcement which can be processed on a reliable basis and can be readily adoptable for high-volume production. Another desire from the industry is the ultrafast curing of these matrix resins. The pre-molding articles may be stored for a long time before they are used in parts manufacturing. During storage, a reactive system is sometimes designed to fast and/or progressively react at room temperature to change the molecular weight of the pre-molding article polymer and hence the process capabilities of the pre-molding articles. In other times, pre-molding articles are stored in a freezer to avoid or slow down potential reactions until the pre-molding articles are ready to be used. As such, there is a need for new materials, systems, and processes for preparing fiber reinforced thermoset composites.